Humans require at least 49 nutrients to meet their metabolic needs. Inadequate consumption of even one of these nutrients will result in adverse metabolic disturbances leading to sickness, poor health, impaired development in children, and large economic costs to society (Branca and Ferrari, Annals of Nutrition and Metabolism, 46:8-17 (2002); Golden, Acta Paediatrica Scandinavica, 374:95-110 (1991); Ramakrishnan, et al., Nutrition Research, 19: 103-159 (1999)). Importantly, the primary source of all nutrients for people comes from agricultural products. If agricultural systems fail to provide enough products containing adequate quantities of all nutrients during all seasons, dysfunctional food systems result that cannot support healthy lives. Unfortunately, this is the case for many agricultural systems in many developing nations in the Global South (Graham, et al., Advances in Agronomy, 70:77-142 (2001); Schneeman, Journal of the Science of Food and Agriculture, 81:3-9 (2001)).
Nearly two-thirds of all deaths of children are associated with nutritional deficiencies, many from micronutrient deficiencies (Caballero, Annals of Nutrition and Metabolism, 46:3-7 (2002)). Marginal intakes of micronutrients have been shown to contribute to increased morbidity and mortality rates, diminished livelihoods, and adverse effects on learning ability, development, and growth in infants and children. Much of childhood stunting has been attributed to the impact of micronutrient deficiencies on children from early fetal stages of development through the fourth year of life (Branca and Ferrari, Annals of Nutrition and Metabolism, 46:8-17 (2002)). By any measure, micronutrient malnutrition is currently of alarming proportions in many developing nations.
Vitamin A, a necessary micronutrient obtained from diet in the form of provitamin A, is important to the human immune and visual systems. Its deficiency leads to the death of 1 million children annually, as well as to eye damage and blindness in 1.3 million children in Africa alone. Estimates by the World Health Organization place 100 to 140 million children as high risk for vitamin A deficiency, and 4 million as having severe vitamin A deficiency. Vitamin A deficiency may increase the risk of maternal mortality in pregnant women. Nearly 600,000 women die from childbirth-related causes each year, the vast majority of them from complications which could be reduced through better nutrition, such as vitamin A.
Current attempts to eradicate vitamin A deficiency in the most needy populations in South Asia and Sub-Saharan Africa focus on supplement distribution. This is a partnership between the local government, NGOs, and even the private sector to set up the appropriate infrastructure and resources for the distribution of vitamin A supplements on what is most commonly a quarterly or biannual basis (The United Nations Children's Fund, http://www.childinfo.org/vitamina.html, Nov. 11, 2008). However, these programs, while alleviating suffering and deprivation in many areas, succumb to a common pitfall: none allow for self-sustenance of the population at risk, instead inadvertently promoting their reliance on the distributors. Furthermore, consistent distribution of supplements requires the deployment of manpower from the local government on a frequent basis, which inevitably increases costs, thereby making these programs less effective.
Several alternatives have relatively recently been proposed to address the problem of non-self-sufficiency. These include the genetically modified “Golden Rice”—rice engineered to overproduce beta-carotene (provitamin A), and programs to promote the planting of sweet potatoes, which is a good vitamin A source. However, both of these solutions come with their own problems. Both require tending of crops, which necessitates vast resources in the form of land, manpower, and water. Also, in both cases, the edible parts are small compared to the whole plant, which is useless after harvest, and the regeneration time of a new plant generation is long (months). Further, yields depend on climate conditions and are not readily controllable. Most importantly, however, is the fact that planting these crops in the hopes of obtaining a sustained vitamin A source often precludes the planting of other plant species for commercial purposes. People cannot plant other things to be sold to the local market because their land has been used to grow rice or sweet potatoes. In light of these deficiencies, a new foodstuff that can serve as a more efficient source of provitamin A is highly desirable.
Therefore, it is an object of the invention to provide alternative renewable food sources of provitamin A that have a fast generation time, grow in a wide variety of conditions, and use less land, water and manpower to grow than most commercial crops.
It is another object of the present invention to provide more efficient and less expensive methods for preventing vitamin A deficiency and diseases and disorders associated therewith.